#define _CRT_SECURE_NO_WARNINGS 1
#include<stdio.h>
int main() {

    int arr[4] = { 0 };
    for (int i = 0; i < 4; i++) {
        scanf("%d", &arr[i]);
    }
    for (int i = 0; i < 4; i++) {
        if (arr[i] >= arr[0]) {
            arr[0] = arr[i];
        }
    }
    printf("%d", arr[0]);
    return 0;
}